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  • Publication . Article . Other literature type . Research . Preprint . 2021
    Open Access
    Authors: 
    Ayse Polatoz; Willard Johns; Sinan Sagir; Soureek Mitra; Michael Tytgat; Ram Krishna Dewanjee; Austin Baty; Graham Wilson; Attilio Santocchia; Erhan Gülmez; +552 more
    Countries: United Kingdom, Spain, Italy, Croatia, Serbia, United States, Turkey, Italy, France, Croatia ...
    Project: EC | AMVA4NewPhysics (675440), EC | INSIGHTS (765710), EC | LHCTOPVLQ (752730)

    Evidence for Higgs boson decay to a pair of muons is presented. This result combines searches in four exclusive categories targeting the production of the Higgs boson via gluon fusion, via vector boson fusion, in association with a vector boson, and in association with a top quark-antiquark pair. The analysis is performed using proton-proton collision data at s√ = 13 TeV, corresponding to an integrated luminosity of 137 fb−1, recorded by the CMS experiment at the CERN LHC. An excess of events over the back- ground expectation is observed in data with a significance of 3.0 standard deviations, where the expectation for the standard model (SM) Higgs boson with mass of 125.38 GeV is 2.5. The combination of this result with that from data recorded at s√ = 7 and 8 TeV, corresponding to integrated luminosities of 5.1 and 19.7 fb−1, respectively, increases both the expected and observed significances by 1%. The measured signal strength, relative to the SM prediction, is 1.19+0.40−0.39(stat)+0.15−0.14(syst). This result constitutes the first evidence for the decay of the Higgs boson to second generation fermions and is the most precise measurement of the Higgs boson coupling to muons reported to date. Individuals have received support from the Marie-Curie programme and the European Research Council and Horizon 2020 Grant, contract Nos. 675440, 752730, and 765710 (European Union); the Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia María de Maeztu, grant MDM-2015-0509 and the Programa Severo Ochoa del Principado de Asturias. CMS collaboration: et al. Peer reviewed

  • Publication . Article . Other literature type . Research . Preprint . 2020
    Open Access English
    Authors: 
    Valerie Domcke; Marco Drewes; Marco Hufnagel; Michele Lucente;
    Publisher: RWTH Aachen University
    Countries: Switzerland, Germany
    Project: EC | NewAve (638528)

    We study the type-I seesaw model with three right-handed neutrinos and Majorana masses below the pion mass. In this mass range, the model parameter space is not only strongly constrained by the requirement to explain the light neutrino masses, but also by experimental searches and cosmological considerations. In the existing literature, three disjoint regions of potentially viable parameter space have been identified. In one of them, all heavy neutrinos decay shortly before big bang nucleosynthesis. In the other two regions, one of the heavy neutrinos either decays between BBN and the CMB decoupling or is quasi-stable. We show that previously unaccounted constraints from photodisintegration of nuclei practically rule out all relevant decays that happen between BBN and the CMB decoupling. Quite remarkably, if all heavy neutrinos decay before BBN, the baryon asymmetry of the universe can be quite generically explained by low-scale leptogenesis, i.e. without further tuning in addition to what is needed to avoid experimental and cosmological constraints. This motivates searches for heavy neutrinos in pion decay experiments. Journal of high energy physics 01(1), 200 (2021). doi:10.1007/JHEP01(2021)200 Published by SISSA, [Trieste]

  • Publication . Conference object . Research . 2018
    Restricted English
    Authors: 
    Livesu, M.; Cabiddu, D.; Attene, M.;
    Publisher: The Eurographics Association, Goslar, DEU
    Country: Italy
    Project: EC | CAxMan (680448)

    Accurately simulating Additive Manufacturing (AM) processes is useful to predict printing failures and test 3D printing without wasting precious resources, both in terms of time ad material. In AM the object to be fabricated is first cut into a set of slices aligned with the build direction, and then printed, depositing or solidifying material one layer on top of the other. To guarantee accurate simulations, it is therefore necessary to encode the temporal evolution of the shape to be printed within the simulation domain. We introduce slice2mesh, to the best of our knowledge the first software capable of turning a sliced object directly into a volumetric mesh. Our tool inputs a set of slices and produces a tetrahedral mesh that endows each slice in its connectivity. An accurate representation of the simulation domain at any time during the print can therefore be easily obtained by filtering out the slices yet to be processed. slice2mesh also features a flexible mesh generation system for external supports, and allows the user to trade accuracy for simplicity by producing approximate simulation domains obtained by filtering the object in slice space. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture/Image Generation-Line and curve generation Smart Tools and Apps for Graphics - Eurographics Italian Chapter Conference M. Livesu, D. Cabiddu, and M. Attene Manufacturing Objects 23 13

  • Publication . Article . Preprint . Other literature type . Research . Report . 2018
    Open Access English
    Authors: 
    Marko Dragicevic; Manfred Jeitler; I Kraetschmer; Jochen Schieck; Johannes Wittmann; Claudia-Elisabeth Wulz; Jasper Lauwers; Freya Blekman; Kevin Deroover; Stefaan Tavernier; +449 more
    Countries: Belgium, United States, France, Germany, Croatia, Italy, Italy, France, France, Lithuania ...
    Project: EC | AMVA4NewPhysics (675440)

    A search for charged Higgs boson decaying to a charm and a bottom quark ( $ {\mathrm{H}}^{+}\to \mathrm{c}\overline{\mathrm{b}} $ ) is performed using 19.7 fb$^{−1}$ of pp collision data at $ \sqrt{s}=8 $ TeV. The production mechanism investigated in this search is $ \mathrm{t}\overline{\mathrm{t}} $ pair production in which one top quark decays to a charged Higgs boson and a bottom quark and the other decays to a charged lepton, a neutrino, and a bottom quark. Charged Higgs boson decays to $ \mathrm{c}\overline{\mathrm{b}} $ are searched for, resulting in a final state containing at least four jets, a charged lepton (muon or electron), and missing transverse momentum. A kinematic fit is performed to identify the pair of jets least likely to be the bottom quarks originating from direct top quark decays and the invariant mass of this pair is used as the final observable in the search. No evidence for the presence of a charged Higgs boson is observed and upper limits at 95% confidence level of 0.8–0.5% are set on the branching fraction ℬ(t → H$^{+}$b), assuming ℬ(H$^{+}$ → $ \mathrm{c}\overline{\mathrm{b}} $ ) = 1.0 and ℬ(t → H$^{+}$b) + ℬ(t → Wb) = 1.0, for the charged Higgs boson mass range 90–150 GeV. Journal of high energy physics 1811(11), 115 (2018). doi:10.1007/JHEP11(2018)115 Published by Springer Nature, Cham

  • Publication . Other literature type . Article . Research . Preprint . 2021
    Open Access English
    Authors: 
    Fruehwirth, Rudolf; Wulz, Claudia-Elisabeth; Melo da Costa, Eliza; Brandao Malbouisson, Helena; Tomei, Thiago; de Moraes Gregores, Eduardo; de Souza Lemos, Dener; Garcia Fuentes, Francisco Ignacio; Agram, Jean-Laurent; Brom, Jean-Marie; +279 more
    Publisher: Elsevier
    Countries: Italy, Germany, Belgium, Italy, Turkey, Croatia, United States, Spain, Turkey, Italy ...
    Project: EC | LHCTOPVLQ (752730), EC | INSIGHTS (765710), EC | AMVA4NewPhysics (675440)

    Measurements of the second Fourier harmonic coefficient (v2) of the azimuthal distributions of prompt and nonprompt D0 mesons produced in pp and pPb collisions are presented. Nonprompt D0 mesons come from beauty hadron decays. The data samples are collected by the CMS experiment at nucleon-nucleon center-of-mass energies of 13 and 8.16 TeV, respectively. In high multiplicity pp collisions, v2 signals for prompt charm hadrons are reported for the first time, and are found to be comparable to those for light-flavor hadron species over a transverse momentum (pT) range of 2–6 GeV. Compared at similar event multiplicities, the prompt D0 meson v2 values in pp and pPb collisions are similar in magnitude. The v2 values for open beauty hadrons are extracted for the first time via nonprompt D0 mesons in pPb collisions. For pT in the range of 2–5 GeV, the results suggest that v2 for nonprompt D0 mesons is smaller than that for prompt D0 mesons. These new measurements indicate a positive charm hadron v2 in pp collisions and suggest a mass dependence in v2 between charm and beauty hadrons in the pPb system. These results provide insights into the origin of heavy-flavor quark collectivity in small systems. Individuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contract Nos. 675440, 752730, and 765710 (European Union); CERN; the Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia María de Maeztu, grant MDM-2015-0509 and the Programa Severo Ochoa del Principado de Asturias. CMS Collaboration: et al. Funded by SCOAP3. Peer reviewed

  • Open Access English
    Authors: 
    Thomas Bergauer; Marko Dragicevic; M. Flechl; Ilse Krätschmer; Dietrich Liko; Thomas Madlener; Jochen Schieck; Robert Schöfbeck; Markus Spanring; Jasper Lauwers; +413 more
    Publisher: Springer Verlag
    Countries: Germany, Germany, United Kingdom, Serbia, France, Italy, Italy, Finland, Switzerland, Italy ...
    Project: EC | AMVA4NewPhysics (675440)

    A search for the standard model Higgs boson produced in association with a W or a Z boson and decaying to a pair of τ leptons is performed. A data sample of proton-proton collisions collected at s√ = 13 TeV by the CMS experiment at the CERN LHC is used, corresponding to an integrated luminosity of 35.9 fb−1. The signal strength is measured relative to the expectation for the standard model Higgs boson, yielding μ = 2.5 − 1.3 + 1.4 . These results are combined with earlier CMS measurements targeting Higgs boson decays to a pair of τ leptons, performed with the same data set in the gluon fusion and vector boson fusion production modes. The combined signal strength is μ = 1.24 − 0.27 + 0.29 (1.00 − 0.23 + 0.24 expected), and the observed significance is 5.5 standard deviations (4.8 expected) for a Higgs boson mass of 125 GeV. Journal of High Energy Physics, 2019 (6) ISSN:1029-8479 ISSN:1126-6708

  • Open Access English
    Authors: 
    Tsitsokas, Dimitrios; Kouvelas, Anastasios; id_orcid0000-0003-4571-2530; Geroliminis, Nikolas;
    Publisher: ETH Zurich
    Country: Switzerland
    Project: EC | DIT4TraM (953783)

    Traffic-responsive signal control is a cost-effective and easy-to-implement network management strategy with high potential in improving performance in congested networks with dynamic characteristics. Max Pressure (MP) distributed controller gained significant popularity due to its theoretically proven ability of queue stabilization and throughput maximization under specific assumptions. However, its effectiveness under saturated conditions is questionable, while network-wide application is limited due to high instrumentation cost. Perimeter control (PC) based on the concept of the Macroscopic Fundamental Diagram (MFD) is a state-of-the-art aggregated strategy that regulates exchange flows between regions, in order to maintain maximum regional travel production and prevent over-saturation. Yet, homogeneity assumption is hardly realistic in congested states, thus compromising PC efficiency. In this paper, the effectiveness of network-wide, parallel application of PC and MP embedded in a two-layer control framework is assessed with mesoscopic simulation. Aiming at reducing implementation cost of MP without significant performance loss, we propose a method to identify critical nodes for partial MP deployment. A modified version of Store-and-forward paradigm incorporating finite queue and spill-back consideration is used to test different configurations of the proposed framework, for a real large-scale network, in moderately and highly congested scenarios. Results show that: (i) combined control of MP and PC outperforms separate MP and PC applications in both demand scenarios; (ii) MP control in reduced critical node sets leads to similar or even better performance compared to full-network implementation, thus allowing for significant cost reduction; iii) the proposed control schemes improve system performance even under demand fluctuations of up to 20% of mean. arXiv

  • Open Access English
    Authors: 
    Kopelyan, Sofya; Nieth, Lisa Johanna;
    Country: Netherlands
    Project: EC | RUNIN (722295)

    A well-functioning regional innovation system involves a lot of communication and interaction among the actors. However, sometimes the communication and interaction create tensions impeding regional development. In order to explore the reasons behind this, this study looks at the relationships between key stakeholders in the Twente Region in the Netherlands. The region has an established reputation for innovation and entrepreneurship, a high inter-connectedness between the actors, and a strong knowledge infrastructure. The research focuses on the University of Twente as a key actor contributing to regional growth in close cooperation with various stakeholders. This is an introductory interview-based case study that identifies four areas of tension between the university and its regional stakeholders. Our inquiry sheds light on the misalignment of stakeholders’ interests and expectations that lessens the actors’ capacity for policy formulation and strategic agenda setting, as well as hinders its successful translation into action. Then, the absence of clear intermediaries significantly increases the perceived distance between the University of Twente and the Twente region and impedes the university’s collaboration with companies outside the science and business park. Next, the tension of discontinuity highlights the complexities of human resources and personalised networks – their diversity, multidimensionality, and overlaps make it harder to synchronise action and enhance reciprocal benefits. The knowledge asymmetry between the parties further complicates their communication and weakens commitment. In the end, the paper offers a few ideas for action for academic leaders and regional policymakers.

  • Publication . Article . Other literature type . Preprint . Research . 2022
    Open Access English
    Authors: 
    Tumasyan, Armen; Adam, Wolfgang; Lechner, Lukas; Hensel, Carsten; Kim, Dong Hee; Kim, Gui Nyun; Kim, Jiwoong; Lee, Jeongeun; Lee, Seh Wook; Moon, Chang-Seong; +524 more
    Publisher: SPRINGER
    Countries: Germany, Germany, France, United Kingdom, Turkey, Italy, Finland, Switzerland, United States, Germany ...
    Project: EC | AMVA4NewPhysics (675440), EC | MajorNet (758316)

    Measurements of jet substructure describing the composition of quark- and gluon-initiated jets are presented. Proton-proton (pp) collision data at √s = 13 TeV collected with the CMS detector are used, corresponding to an integrated luminosity of 35.9 fb−1. Generalized angularities are measured that characterize the jet substructure and distinguish quark- and gluon-initiated jets. These observables are sensitive to the distributions of transverse momenta and angular distances within a jet. The analysis is performed using a data sample of dijet events enriched in gluon-initiated jets, and, for the first time, a Z+jet event sample enriched in quark-initiated jets. The observables are measured in bins of jet transverse momentum, and as a function of the jet radius parameter. Each measurement is repeated applying a “soft drop” grooming procedure that removes soft and large angle radiation from the jet. Using these measurements, the ability of various models to describe jet substructure is assessed, showing a clear need for improvements in Monte Carlo generators. Journal of High Energy Physics, 2022 (1) ISSN:1029-8479 ISSN:1126-6708

  • Open Access English
    Authors: 
    Jürgen Zechner; Lars Kielhorn; Thomas Rüberg; Soner Steiner;
    Publisher: Zenodo
    Project: EC | PRACE-6IP (823767)

    TAILSIT is a company based in Graz, Austria, that produces custom-fit simulation software tools for computational electromagnetics and structural analysis. Its unique selling proposition is a numerical software library based on a coupled Finite/Boundary Element Method (FEM/BEM) for the efficient analysis of electromagnetic problems. A major building block of the software is represented by the BEM which, in its naive implementation, has a quadratic complexity: runtime and memory requirements scale with the second power of the system size. In order to overcome this limitation, TAILSIT uses the Fast Multipole Method (FMM) where the scaling of the computational costs reduce to almost linear complexity. But even with this acceleration technique, the use of the BEM is rather limited on an average desktop workstation. During this SHAPE project TAILSIT’s electromagnetic simulation software has been ported to HPC machines with the support of the Vienna Scientific Cluster (VSC, https://vsc.ac.at) at TU Wien and using their computing resources. Thorough performance analyses have led to significant runtime improvements and a good overall scaling for up to a few thousand CPUs. Whereas TAILSIT’s previous implementation of the FMM could handle about 106 degrees of freedom, within this project we achieved problem sizes of up to 50 · 10.

Advanced search in
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1,618 Research products, page 1 of 162
  • Publication . Article . Other literature type . Research . Preprint . 2021
    Open Access
    Authors: 
    Ayse Polatoz; Willard Johns; Sinan Sagir; Soureek Mitra; Michael Tytgat; Ram Krishna Dewanjee; Austin Baty; Graham Wilson; Attilio Santocchia; Erhan Gülmez; +552 more
    Countries: United Kingdom, Spain, Italy, Croatia, Serbia, United States, Turkey, Italy, France, Croatia ...
    Project: EC | AMVA4NewPhysics (675440), EC | INSIGHTS (765710), EC | LHCTOPVLQ (752730)

    Evidence for Higgs boson decay to a pair of muons is presented. This result combines searches in four exclusive categories targeting the production of the Higgs boson via gluon fusion, via vector boson fusion, in association with a vector boson, and in association with a top quark-antiquark pair. The analysis is performed using proton-proton collision data at s√ = 13 TeV, corresponding to an integrated luminosity of 137 fb−1, recorded by the CMS experiment at the CERN LHC. An excess of events over the back- ground expectation is observed in data with a significance of 3.0 standard deviations, where the expectation for the standard model (SM) Higgs boson with mass of 125.38 GeV is 2.5. The combination of this result with that from data recorded at s√ = 7 and 8 TeV, corresponding to integrated luminosities of 5.1 and 19.7 fb−1, respectively, increases both the expected and observed significances by 1%. The measured signal strength, relative to the SM prediction, is 1.19+0.40−0.39(stat)+0.15−0.14(syst). This result constitutes the first evidence for the decay of the Higgs boson to second generation fermions and is the most precise measurement of the Higgs boson coupling to muons reported to date. Individuals have received support from the Marie-Curie programme and the European Research Council and Horizon 2020 Grant, contract Nos. 675440, 752730, and 765710 (European Union); the Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia María de Maeztu, grant MDM-2015-0509 and the Programa Severo Ochoa del Principado de Asturias. CMS collaboration: et al. Peer reviewed

  • Publication . Article . Other literature type . Research . Preprint . 2020
    Open Access English
    Authors: 
    Valerie Domcke; Marco Drewes; Marco Hufnagel; Michele Lucente;
    Publisher: RWTH Aachen University
    Countries: Switzerland, Germany
    Project: EC | NewAve (638528)

    We study the type-I seesaw model with three right-handed neutrinos and Majorana masses below the pion mass. In this mass range, the model parameter space is not only strongly constrained by the requirement to explain the light neutrino masses, but also by experimental searches and cosmological considerations. In the existing literature, three disjoint regions of potentially viable parameter space have been identified. In one of them, all heavy neutrinos decay shortly before big bang nucleosynthesis. In the other two regions, one of the heavy neutrinos either decays between BBN and the CMB decoupling or is quasi-stable. We show that previously unaccounted constraints from photodisintegration of nuclei practically rule out all relevant decays that happen between BBN and the CMB decoupling. Quite remarkably, if all heavy neutrinos decay before BBN, the baryon asymmetry of the universe can be quite generically explained by low-scale leptogenesis, i.e. without further tuning in addition to what is needed to avoid experimental and cosmological constraints. This motivates searches for heavy neutrinos in pion decay experiments. Journal of high energy physics 01(1), 200 (2021). doi:10.1007/JHEP01(2021)200 Published by SISSA, [Trieste]

  • Publication . Conference object . Research . 2018
    Restricted English
    Authors: 
    Livesu, M.; Cabiddu, D.; Attene, M.;
    Publisher: The Eurographics Association, Goslar, DEU
    Country: Italy
    Project: EC | CAxMan (680448)

    Accurately simulating Additive Manufacturing (AM) processes is useful to predict printing failures and test 3D printing without wasting precious resources, both in terms of time ad material. In AM the object to be fabricated is first cut into a set of slices aligned with the build direction, and then printed, depositing or solidifying material one layer on top of the other. To guarantee accurate simulations, it is therefore necessary to encode the temporal evolution of the shape to be printed within the simulation domain. We introduce slice2mesh, to the best of our knowledge the first software capable of turning a sliced object directly into a volumetric mesh. Our tool inputs a set of slices and produces a tetrahedral mesh that endows each slice in its connectivity. An accurate representation of the simulation domain at any time during the print can therefore be easily obtained by filtering out the slices yet to be processed. slice2mesh also features a flexible mesh generation system for external supports, and allows the user to trade accuracy for simplicity by producing approximate simulation domains obtained by filtering the object in slice space. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture/Image Generation-Line and curve generation Smart Tools and Apps for Graphics - Eurographics Italian Chapter Conference M. Livesu, D. Cabiddu, and M. Attene Manufacturing Objects 23 13

  • Publication . Article . Preprint . Other literature type . Research . Report . 2018
    Open Access English
    Authors: 
    Marko Dragicevic; Manfred Jeitler; I Kraetschmer; Jochen Schieck; Johannes Wittmann; Claudia-Elisabeth Wulz; Jasper Lauwers; Freya Blekman; Kevin Deroover; Stefaan Tavernier; +449 more
    Countries: Belgium, United States, France, Germany, Croatia, Italy, Italy, France, France, Lithuania ...
    Project: EC | AMVA4NewPhysics (675440)

    A search for charged Higgs boson decaying to a charm and a bottom quark ( $ {\mathrm{H}}^{+}\to \mathrm{c}\overline{\mathrm{b}} $ ) is performed using 19.7 fb$^{−1}$ of pp collision data at $ \sqrt{s}=8 $ TeV. The production mechanism investigated in this search is $ \mathrm{t}\overline{\mathrm{t}} $ pair production in which one top quark decays to a charged Higgs boson and a bottom quark and the other decays to a charged lepton, a neutrino, and a bottom quark. Charged Higgs boson decays to $ \mathrm{c}\overline{\mathrm{b}} $ are searched for, resulting in a final state containing at least four jets, a charged lepton (muon or electron), and missing transverse momentum. A kinematic fit is performed to identify the pair of jets least likely to be the bottom quarks originating from direct top quark decays and the invariant mass of this pair is used as the final observable in the search. No evidence for the presence of a charged Higgs boson is observed and upper limits at 95% confidence level of 0.8–0.5% are set on the branching fraction ℬ(t → H$^{+}$b), assuming ℬ(H$^{+}$ → $ \mathrm{c}\overline{\mathrm{b}} $ ) = 1.0 and ℬ(t → H$^{+}$b) + ℬ(t → Wb) = 1.0, for the charged Higgs boson mass range 90–150 GeV. Journal of high energy physics 1811(11), 115 (2018). doi:10.1007/JHEP11(2018)115 Published by Springer Nature, Cham

  • Publication . Other literature type . Article . Research . Preprint . 2021
    Open Access English
    Authors: 
    Fruehwirth, Rudolf; Wulz, Claudia-Elisabeth; Melo da Costa, Eliza; Brandao Malbouisson, Helena; Tomei, Thiago; de Moraes Gregores, Eduardo; de Souza Lemos, Dener; Garcia Fuentes, Francisco Ignacio; Agram, Jean-Laurent; Brom, Jean-Marie; +279 more
    Publisher: Elsevier
    Countries: Italy, Germany, Belgium, Italy, Turkey, Croatia, United States, Spain, Turkey, Italy ...
    Project: EC | LHCTOPVLQ (752730), EC | INSIGHTS (765710), EC | AMVA4NewPhysics (675440)

    Measurements of the second Fourier harmonic coefficient (v2) of the azimuthal distributions of prompt and nonprompt D0 mesons produced in pp and pPb collisions are presented. Nonprompt D0 mesons come from beauty hadron decays. The data samples are collected by the CMS experiment at nucleon-nucleon center-of-mass energies of 13 and 8.16 TeV, respectively. In high multiplicity pp collisions, v2 signals for prompt charm hadrons are reported for the first time, and are found to be comparable to those for light-flavor hadron species over a transverse momentum (pT) range of 2–6 GeV. Compared at similar event multiplicities, the prompt D0 meson v2 values in pp and pPb collisions are similar in magnitude. The v2 values for open beauty hadrons are extracted for the first time via nonprompt D0 mesons in pPb collisions. For pT in the range of 2–5 GeV, the results suggest that v2 for nonprompt D0 mesons is smaller than that for prompt D0 mesons. These new measurements indicate a positive charm hadron v2 in pp collisions and suggest a mass dependence in v2 between charm and beauty hadrons in the pPb system. These results provide insights into the origin of heavy-flavor quark collectivity in small systems. Individuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contract Nos. 675440, 752730, and 765710 (European Union); CERN; the Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia María de Maeztu, grant MDM-2015-0509 and the Programa Severo Ochoa del Principado de Asturias. CMS Collaboration: et al. Funded by SCOAP3. Peer reviewed

  • Open Access English
    Authors: 
    Thomas Bergauer; Marko Dragicevic; M. Flechl; Ilse Krätschmer; Dietrich Liko; Thomas Madlener; Jochen Schieck; Robert Schöfbeck; Markus Spanring; Jasper Lauwers; +413 more
    Publisher: Springer Verlag
    Countries: Germany, Germany, United Kingdom, Serbia, France, Italy, Italy, Finland, Switzerland, Italy ...
    Project: EC | AMVA4NewPhysics (675440)

    A search for the standard model Higgs boson produced in association with a W or a Z boson and decaying to a pair of τ leptons is performed. A data sample of proton-proton collisions collected at s√ = 13 TeV by the CMS experiment at the CERN LHC is used, corresponding to an integrated luminosity of 35.9 fb−1. The signal strength is measured relative to the expectation for the standard model Higgs boson, yielding μ = 2.5 − 1.3 + 1.4 . These results are combined with earlier CMS measurements targeting Higgs boson decays to a pair of τ leptons, performed with the same data set in the gluon fusion and vector boson fusion production modes. The combined signal strength is μ = 1.24 − 0.27 + 0.29 (1.00 − 0.23 + 0.24 expected), and the observed significance is 5.5 standard deviations (4.8 expected) for a Higgs boson mass of 125 GeV. Journal of High Energy Physics, 2019 (6) ISSN:1029-8479 ISSN:1126-6708

  • Open Access English
    Authors: 
    Tsitsokas, Dimitrios; Kouvelas, Anastasios; id_orcid0000-0003-4571-2530; Geroliminis, Nikolas;
    Publisher: ETH Zurich
    Country: Switzerland
    Project: EC | DIT4TraM (953783)

    Traffic-responsive signal control is a cost-effective and easy-to-implement network management strategy with high potential in improving performance in congested networks with dynamic characteristics. Max Pressure (MP) distributed controller gained significant popularity due to its theoretically proven ability of queue stabilization and throughput maximization under specific assumptions. However, its effectiveness under saturated conditions is questionable, while network-wide application is limited due to high instrumentation cost. Perimeter control (PC) based on the concept of the Macroscopic Fundamental Diagram (MFD) is a state-of-the-art aggregated strategy that regulates exchange flows between regions, in order to maintain maximum regional travel production and prevent over-saturation. Yet, homogeneity assumption is hardly realistic in congested states, thus compromising PC efficiency. In this paper, the effectiveness of network-wide, parallel application of PC and MP embedded in a two-layer control framework is assessed with mesoscopic simulation. Aiming at reducing implementation cost of MP without significant performance loss, we propose a method to identify critical nodes for partial MP deployment. A modified version of Store-and-forward paradigm incorporating finite queue and spill-back consideration is used to test different configurations of the proposed framework, for a real large-scale network, in moderately and highly congested scenarios. Results show that: (i) combined control of MP and PC outperforms separate MP and PC applications in both demand scenarios; (ii) MP control in reduced critical node sets leads to similar or even better performance compared to full-network implementation, thus allowing for significant cost reduction; iii) the proposed control schemes improve system performance even under demand fluctuations of up to 20% of mean. arXiv

  • Open Access English
    Authors: 
    Kopelyan, Sofya; Nieth, Lisa Johanna;
    Country: Netherlands
    Project: EC | RUNIN (722295)

    A well-functioning regional innovation system involves a lot of communication and interaction among the actors. However, sometimes the communication and interaction create tensions impeding regional development. In order to explore the reasons behind this, this study looks at the relationships between key stakeholders in the Twente Region in the Netherlands. The region has an established reputation for innovation and entrepreneurship, a high inter-connectedness between the actors, and a strong knowledge infrastructure. The research focuses on the University of Twente as a key actor contributing to regional growth in close cooperation with various stakeholders. This is an introductory interview-based case study that identifies four areas of tension between the university and its regional stakeholders. Our inquiry sheds light on the misalignment of stakeholders’ interests and expectations that lessens the actors’ capacity for policy formulation and strategic agenda setting, as well as hinders its successful translation into action. Then, the absence of clear intermediaries significantly increases the perceived distance between the University of Twente and the Twente region and impedes the university’s collaboration with companies outside the science and business park. Next, the tension of discontinuity highlights the complexities of human resources and personalised networks – their diversity, multidimensionality, and overlaps make it harder to synchronise action and enhance reciprocal benefits. The knowledge asymmetry between the parties further complicates their communication and weakens commitment. In the end, the paper offers a few ideas for action for academic leaders and regional policymakers.

  • Publication . Article . Other literature type . Preprint . Research . 2022
    Open Access English
    Authors: 
    Tumasyan, Armen; Adam, Wolfgang; Lechner, Lukas; Hensel, Carsten; Kim, Dong Hee; Kim, Gui Nyun; Kim, Jiwoong; Lee, Jeongeun; Lee, Seh Wook; Moon, Chang-Seong; +524 more
    Publisher: SPRINGER
    Countries: Germany, Germany, France, United Kingdom, Turkey, Italy, Finland, Switzerland, United States, Germany ...
    Project: EC | AMVA4NewPhysics (675440), EC | MajorNet (758316)

    Measurements of jet substructure describing the composition of quark- and gluon-initiated jets are presented. Proton-proton (pp) collision data at √s = 13 TeV collected with the CMS detector are used, corresponding to an integrated luminosity of 35.9 fb−1. Generalized angularities are measured that characterize the jet substructure and distinguish quark- and gluon-initiated jets. These observables are sensitive to the distributions of transverse momenta and angular distances within a jet. The analysis is performed using a data sample of dijet events enriched in gluon-initiated jets, and, for the first time, a Z+jet event sample enriched in quark-initiated jets. The observables are measured in bins of jet transverse momentum, and as a function of the jet radius parameter. Each measurement is repeated applying a “soft drop” grooming procedure that removes soft and large angle radiation from the jet. Using these measurements, the ability of various models to describe jet substructure is assessed, showing a clear need for improvements in Monte Carlo generators. Journal of High Energy Physics, 2022 (1) ISSN:1029-8479 ISSN:1126-6708

  • Open Access English
    Authors: 
    Jürgen Zechner; Lars Kielhorn; Thomas Rüberg; Soner Steiner;
    Publisher: Zenodo
    Project: EC | PRACE-6IP (823767)

    TAILSIT is a company based in Graz, Austria, that produces custom-fit simulation software tools for computational electromagnetics and structural analysis. Its unique selling proposition is a numerical software library based on a coupled Finite/Boundary Element Method (FEM/BEM) for the efficient analysis of electromagnetic problems. A major building block of the software is represented by the BEM which, in its naive implementation, has a quadratic complexity: runtime and memory requirements scale with the second power of the system size. In order to overcome this limitation, TAILSIT uses the Fast Multipole Method (FMM) where the scaling of the computational costs reduce to almost linear complexity. But even with this acceleration technique, the use of the BEM is rather limited on an average desktop workstation. During this SHAPE project TAILSIT’s electromagnetic simulation software has been ported to HPC machines with the support of the Vienna Scientific Cluster (VSC, https://vsc.ac.at) at TU Wien and using their computing resources. Thorough performance analyses have led to significant runtime improvements and a good overall scaling for up to a few thousand CPUs. Whereas TAILSIT’s previous implementation of the FMM could handle about 106 degrees of freedom, within this project we achieved problem sizes of up to 50 · 10.

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